1. Field of the Invention
This invention relates generally to pallets and more particularly to pallet assemblies made from components or runners that are easily interconnected and locked into place.
2. Description of the Prior Art
Representative examples of this art include U.S. Pat. No. 3,654,877 to Barrett which discloses a pallet with spaced round or square base members and smaller cross members that are held in place by dowel pins. The variety of sizes of base members, the required spatial relation among the members and the use of dowel pins to hold the members together make assembly of this unit complex. Furthermore the different sizes of the base members requires a full compliment of base members should one of the base members break and need to be replaced. U.S. Pat. No. 3,878,796 to Morrison discloses a pallet assembled from boards with notches and shoulders along their length. The notches and shoulders mate with corresponding shoulders and notches in support stringers. This construction suffers from the fact that the boards have no support in the spans between the stringers. The only way that additional stringers can be added or removed is by shifting some of the stringers already installed. The system of notches and shoulders is also susceptible to dirt and breakage.
U.S. Pat. No. 3,927,624 to Hewson discloses a knock down pallet with parallel first beam elements having support posts with notches and second beam elements having support posts with mating slots which engage each other. Such a construction limits the number of beam members per unit area to the spacing of the interconnecting support posts on the first and second beams. U.S. Pat. No. 4,359,948 to Judy, et al. shows interconnecting pallet stringers that use a set of projections and detents on a first set of stringers that mate with slots, locking nipples and ridges on a second set of stringers. Again the number of beam members per unit area is limited by the position of the interconnections. U.S. Pat. No. 4,497,260 to Buche discloses a pallet made from essentially two long beams joined together by cross beams where the members forming the long beam are held together by wedges.
The prior art pallet assemblies have members with complicated construction and complicated interconnecting parts. Some assemblies require special fasteners to interlock the components. The position of the interlocking parts of the pallet members often limits the number of support members that can be used per unit area of the pallet. Moreover the complexity and detail of the interlock mechanism often makes it very difficult to remove broken members and insert new members. The complex detail of the interlock mechanism is also subject to failure as a result of the accumulation of dirt and other foreign matter in the groves, notches, slots, detents, nipples and ridges of the interlock mechanisms.